Picture the stage. A black woman is lying in her underwear while her boyfriend straddles her. Actually, best say a boyfriend, because this woman doesn’t do exclusivity. Over her face, he presses a pillow. Is she enjoying it? Is she in danger? From him, or herself? Finally, the man lifts the pillow. “I can still breathe,” the female character, Prism, says. She means it, on this occasion at least, as a complaint, a spur to greater suffocation.

Prism, who features in American writer and activist Kristiana Rae Colón’s play Octagon, which opens this month at the Arcola Theatre, is a rare example of what the play’s director, Nadia Latif, calls “complicated women” on the stage. “Men have got to do that for generations,” says Latif. “Look at Arthur Miller! Endlessly complicated men, very straightforward women.”

As her name suggests, Prism is designed to provoke a spectrum of responses. How far is she in charge of herself, her desire, her outcomes? “I actually found it quite tough at the beginning to get my head round her,” Latif says, turning from the window of the rehearsal room, where she has been blowing out cigarette smoke. The actors have left for the day. Someone is gathering props and papers in the corner. Only she and Colón remain.

“It’s been really interesting to me – the number of women who have read the script and thought that character is not empowered,” Latif says. “What’s wrong with wanting to live life? I always feel like the word ‘daredevil’ doesn’t apply to women. Only men get to do that. [Prism] is a fucking pioneer, man! She’s the Amelia Earhart of black sex.”

Latif and Colón came across each other in 2008, when Colón, fresh from taking an MFA in creative writing, was scouring the internet for approachable directors. No one got back to her on her script, written “defiantly” in lower case, without punctuation, “in the tradition of Ntozake Shange and the black arts movement of the 60s and 70s”. So Colón sent it to Latif, having read online that the Rada-trained director wanted to hear from American writers.

“I received it at 1am,” Latif says. “I was like, who does this bitch think she is?” Colón is laughing. “She’s riffing on Ntozake. She’s cooool. She’s not interested in inherited rules of language and inherited rules of how plays work.” By 4am, she had sent Colón an email saying: “Let’s do this!” (Four years later, that play – but i cd only whisper – was staged at the Arcola Theatre.) “I was interested in why we select some American stories and not other American stories,” says Latif, “When are we going to get that new generation of black American writers?”

It is a question the play itself tackles. Prism and the seven other characters who form the titular octagon are slam poets, preparing to compete, each arguing in a different way for the purpose of their art. As with Prism, it all begins in their throats: the place where their sound rises, where they breath or don’t breathe, where they give and take their pleasure.

Actors rehearsing for Octagon at the Arcola Theatre, London. Photograph: Sarah Lee for the Guardian

“I am kind of obsessed with the image,” says Colón, 29, who won the 2014 National Latino Playwriting Award with this script. The throat has become the place where all her interests tangle and choke. When, for instance, she co-founded a collective in her home city of Chicago, initially to deliver gas masks to protesters in Ferguson, she called it #LetUsBreathe, echoing the last words of Eric Garner, who was choked to death last year by police in Staten Island. (Garner doesn’t get a mention in the play, though Mike Brown, Sandra Bland and Freddie Gray do.)

All of these forces run through Colón’s play – the alliance of art and activism, the right to unrestrained speech, the deaths of too many black men and women – but her own voice is quiet, measured and focused. The daughter of a former Chicago alderman and an actor-turned-financial consultant, she began to slam at the age of 16 with the Young Chicago Authors group, before going on to national competitions. When she talks, her breath swallows pauses and interruptions. She can string a sentence across a dozen subclauses and a couple of minutes and show no strain.

This is fitting, because Octagon argues strongly for freedom of expression, for the power of poetry to help people imagine a better future. Presumably that is why Colón’s #LetUsBreathe collective went to Ferguson – where she says she wanted to try “to use our artistic capital and our cultural capital to amplify the stories of the people there”. How important is it to Colón that so many high-profile black activists in the US – such as those behind #BlackLivesMatter - are women? And how much difference does that make to their power to levy change?

“If we are going to achieve liberation [so that] every human being can be a full human being freely, then we have to affirm the most marginalised people, and that is always going to be women, queer people, people with disabilities,” she says. “I think there has been a lot of intentionality behind the #BlackLivesMatter movement of not replicating those historical erasures that have happened for generations and generations. One of the reasons the black liberation movement of the 60s and 70s failed was because of the patriarchy and the misogyny, pushing women to the margins and saying, ‘It’s your job to breed the next generation of warriors.’”

There is no direct equivalent of #BlackLivesMatter in the UK, but Latif says she noticed something similar, albeit on a very different scale, at the Focus E15 demonstration. “Owen Jones turned up and Russell Brand turned up, and they felt slightly accessory-like because you had this extraordinary female force at the middle of it going” – she raises her hand – “‘We’ve got this actually. We’re going to speak up for ourselves.’”

These subjects are particularly potent for Latif at the moment. Only five weeks have passed since another play she was directing, Homegrown, which explored why young British people join Islamic State, was unexpectedly cancelled by the National Youth Theatre. “It’s still very raw,” she says. “There’s been a lot of weeping, a lot of therapy.”

“I think we are obsessed with authenticity in British theatre. We [her and Omar El-Khairy]got that job because of perceived authentic voices and actually the whole show was about us saying ‘Boof! Fuck off, we’re not doing that, we’re not playing your game, of this understanding you assume we have because of our cultural narrative.” She says that no one ever asked her if she was a Muslim (“No: atheist”) but believes that assumption is regularly made. She grew up in Sudan, her father’s home country, before moving to England when she was 14.

Latif still doesn’t know why Homegrown was cancelled. She is certain about one thing, though: the experience of having her own creativity silenced has enriched her understanding of Colón’s play, and strengthened her commitment to amplifying its cry for freedom.

Octagon is at the Arcola Theatre, London E8 from 16 September to 17 October. Box office: 020 7503 1646. arcolatheatre.com.